1. Technical Field
The present invention relates in general to the field of data processing systems. More specifically, the present invention relates to the field of securely processing data within data processing systems. Still more specifically, the present invention relates to a system and method for an isolated process to control address translation.
2. Description of the Related Art
The Cell Broadband Engine Architecture (CBEA) and current Cell Broadband implementation provide an application with a secure operating environment called a “Cell Secure Vault”. When in a Secure Vault, an application is required to utilize direct memory access (DMA) to bring information into the vault and authenticate and decrypt the information. Likewise, the application must utilize DMA to send secure or encrypted information to system memory. The addresses of the DMA transfers are translated from an effective address, used by the application running in the Secure Vault, to the physical address of system memory. The translation mechanism is typically setup and managed by software, such as an operating system, which executes outside of the secure vault and thus can not be trusted. Since the address translation can not be trusted, an application running in a secure value can not perform a system monitoring function. To prevent attacks on the computer system after boot, a system monitor can be started in a secure vault as part of a secure boot process. Since the secure vault is more resistant to attacks, the system monitor can continually check the integrity of the operating system and other system resources. The system monitor performs the integrity check by performing DMA transfers from the system memory and verifies that the image is the same as the image at boot. However, since the DMAs can be translated to point to other areas of memory, the attack can simply point the system monitor to an unmodified operating system image.
Therefore, there is a need for a system and method for enabling a system monitoring function to operating within a Secure Vault environment to address the aforementioned limitations of the prior art.